The mother of a little boy who went missing in Manhattan in 1979 has opened up about her son's open and caring nature at the trial of his accused killer, Pedro Hernandez.

Julie Patz, who waved her little boy Etan off on his first solo walk to school on May 25th 1979, said: "That was the last time I saw him. I watched him walk one block away. I turned around and went back upstairs and that was the last time."

Commenting on her six-year-old son's attitude to strangers, she said: "Everyone that he met once was his friend and was a nice person."

And yet, the little boy sometimes expressed concern about being alone, with his mum telling the court: "At the same time he was very fearful of being lost or left alone by himself."

At the time of the little boy's disappearance, a teenage store clerk named Pedro Hernandez was among those interviewed by police in relation to the case, but it wasn't until 2012 that he emerged as a suspect.

A videotaped confession and remarks made to friends in the 1980's flagged Hernandez as a person of interest in the case,

The trial is expected to last up to three months.